1. Field of the Invention
The present invention relates to a folding chair having a friction damping part, and more particularly, to a folding chair having a friction damping part in which a damping part for decelerating a rotary speed of a seat board is disposed at a folding chair, such as a grandstand, having the seat board vertically rotatably supported between a pair of stand frames to reduce noise generation and decrease a possibility of being damaged due to rapid rotation of the seat board and decrease a possibility of accidents caused by the rapidly rotating seat board, while a friction force and elastic force are used in damping to have a simple structure by a mechanical mechanism, be easily manufactured, and guarantee a sufficient damping force.
2. Discussion of Related Art
Generally, a chair for viewing, i.e. a grandstand seat, is installed at a multiuse facility such as various types of stadiums, movie theaters, etc. For efficient space utilization in installing the grandstand seat, a stepped concrete structure is installed, and the grandstand seat is installed on an inclined surface, a wall, or a horizontal surface (floor surface) of the concrete structure.
As disclosed in Korean utility model gazette No. 20-1993-0003026, a foldable chair in which a seat member is folded toward a backrest member is mostly used as the grandstand seat to provide a moving space to enable people to easily pass by.
In a conventional grandstand seat, a fixing bracket was fixed and installed at one side of a seat member using a screw, a fixing shaft formed as above was inserted into a frame, a fixing bracket was inserted into another side of the frame, and a seat board was put on a seat board fastening part of the fixing bracket and fixed and assembled to the bracket by a screw.
The grandstand seat has a torsion spring installed at a rotary shaft of the seat member to enable the seat member to automatically rotate by an elastic force of the torsion spring.
In other words, when a person uses the grandstand seat, the person sits thereon after the seat member rotates in a direction away from the backrest member. When the person stands up, the seat member rotates in a direction toward the backrest member to be folded by an elastic force of the torsion spring.
However, the grandstand seat had a disadvantage of generating noise which disturbs viewing of others as the seat member collides with the backrest member when rotating by the elastic force of the torsion spring, or causing the seat member and the backrest member to be damaged due to an impact caused by the collision, and had a problem of causing accidents by the rapid rotation of the seat member at a chaotic situation caused by many people pouring into a stadium.
To overcome the above disadvantage of the grandstand seat, “Damper for Rotary Chair” has been suggested in Korean Unexamined Patent Application Publication No. 10-2015-0072557.
However, the damper for a rotary chair decelerates a rotary speed of a seating member by filling a filling liquid such as silicone oil having predetermined viscosity into an installation space in which a torsion spring for rotating the seat member by an elastic force is embedded to provide a friction force to the torsion spring, thereby having a possibility of leakage of the filling liquid and thus having a limitation in maintaining a sufficient damping force for a long period, and having a disadvantage of not being able to be installed at a circular grandstand since the seat member cannot be installed at a slant with respect to a frame.